1. Field of the Invention
The present invention relates to a brush alignment platform and, more particularly, to an alignment jig that provides for the disposition of a brush on a roller, in static alignment, by creating a layer of fluid beneath the brush to successively unseat the brush from the roller and bring the brush substantially into static alignment.
2. Description of the Invention Background
As is known in the art, in the course of the process of manufacturing a semiconductor device, impurities will become deposited on the surface of the semiconductor wafer or substrate. If these contaminants are allowed to remain in the wafer throughout the manufacturing process, the quality and the yield of the production process will be negatively affected. Therefore, various cleaning processes are typically employed throughout the manufacturing process in an attempt to eliminate these impurities from the surface of the semiconductor.
One such known cleaning apparatus includes rotating a substantially cylindrical brush, having a plurality of cleaning tips thereon, along the surface of the semiconductor to remove impurities. In practice, the brush has a length equal to or greater than the diameter of the wafer to be cleaned. The cylindrical brush is manually seated onto a roller shaft. The shaft is then mechanically rotated about its axis while being moved along a diameter of the wafer. In the alternative, the wafer itself is also rotated about its center point while the brush is rotated about its axis. In either case, the cleaning tips are brought into contact with the surface of the wafer while a cleaning solution is introduced onto the surface of the wafer. As such, the entire surface of the wafer is contacted and cleaned by the rotating action of the cleaning tips. As described, the cleaning apparatus can be employed to clean either the top or bottom side of the semiconductor wafer. Such wafer cleaning apparatus are known in the art by and sold under the trademark of On-Trak.TM. by On-Trak Systems, Inc. of Milpitas, California.
In such a cleaning apparatus, for the brush to successfully clean the surface of the wafer, it is critical that the brush be evenly disposed along the length of the roller shaft so that the cleaning tips are evenly aligned throughout the surface of the brush. However, due to the need for the brush to be in close communication with the surface of the roller, the inner diameter of the brush is designed to be equal to or less than the outer diameter of the roller. Therefore, it is necessary to manually deform and stretch the brush to fully seat it onto the roller. Manual application of the brush is very difficult to accomplish without twisting and unevenly disposing the brush along the shaft. Such a misalignment of the brush creates an uneven placement of the cleaning tips about the surface area of the brush which ultimately leads to an uneven cleaning of the surface of the wafer by the brush. The most common method of aligning the brush is to manually re-seat it onto the shaft. This method involves applying and aligning the brush by hand. Typically, it is time consuming and only partially effective.
Increasing the inner diameter of the brush will decrease the tendency for the brush to be unevenly disposed along the shaft. However, increasing the diameter of the brush will also decrease the frictional contact between the brush and the shaft. This typically leads to slippage between the brush and the roller which causes premature wearing of the brush and uneven cleaning of the wafer. Thus, increasing the diameter of the brush to eliminate this problem is undesirable. Other methods designed to reduce the misalignment of the brush on the shaft, such as lubricating the points of contact between the brush and the shaft, also lead to such slipping and are thus equally undesirable.
Thus, the only suitable method known in the art of aligning the brush on the roller is to do so by hand. This manual alignment process is typically slow, cumbersome and only partially effective. None of the known cleaning apparatus in the prior art provide an adequate solution to the problem of proper brush alignment.
The subject invention is thus directed toward a brush alignment apparatus and method which addresses, among others, the above-discussed needs and provides an apparatus and method for aligning a cleaning brush on a roller such that it is evenly disposed about the entire surface area of the shaft with minimal effort and time expended by the operator.